Showers and thunderstorms developed in a warm, moist, and unstable air mass. Some of these storms produced some flash flooding.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS JAN wrote it up.
Showers and thunderstorms developed in a warm, moist, and unstable air mass. Some of these storms produced some flash flooding.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Jackson, MS wrote its last area forecast discussion before the first event at May 21, 1:51 PM CST, 2 hours 32 minutes earlier.
Area Forecast Discussion National Weather Service Jackson MS 251 PM CDT Mon May 21 2018 .DISCUSSION... Tonight and Tuesday: The primary focus will be for a summer like pattern with diurnal convection through the period. Scattered afternoon convection will start to diminish once we beging to lose the heat of the day for this evening. Models continue to indicate light flow through the atmospheric column with pwats above 1.5 inches along with instability. This will translate to slow moving storms with locally heavy rainfall with ponding of roadways. Expect the convection to gradually diminish this evening. For Tuesday convection will build in coverage as we go into the heat of the day. Any storms that do develop will build over areas where outflow boundaries were left by todays storms. Expecting scattered coverage during the afternoon. Not seeing any signs of any organized development, so will keep the HWO clear for now. Lows for tonight will be in the middle 60s to the lower 70s. Highs for Tuesday will be from the middle 80s to the lower 90s./17/ Tuesday night through Sunday: The mid level flow pattern will be rather weak and unsettled at the beginning of the period. Mid level ridging off the east coast and over the Plains will eventually lead to broad trough development over the Gulf Coastal states and the Gulf of Mexico by the end of the period. A steady influx of high PW air from the southeast will lead to increasing coverages of diurnal convection each day, especially over the south. This will also lead to earlier onsets of convection and in turn lower maximums. Model solutions differ somewhat moving into the weekend. While the GFS keeps a broad surface low over the southern Gulf, the ECMWF and Canadian strengthen the low and move it briskly toward the north central Gulf Coast Saturday. Despite the variance in solutions, they do agree that an increase in convection will be the trend with heavy rainfall chances increasing as well from the south by the weekend./26/ && .AVIATION... 18Z TAF discussion: VFR flight categories expected to prevail through the course of the day. During the afternoon, another round of showers and storms will be possible across the region, lingering a few hours into tonight. This will again bring about a brief reduction to both ceilings and visibiltiies, thus reducing flight categories MVFR/IFR if observed on-station. Light to calming winds this morning, will give way to winds generally between 3-8 knots from the east by late morning./17/19/ && .PRELIMINARY POINT TEMPS/POPS... Jackson 68 89 69 89 / 27 45 20 32 Meridian 67 89 67 88 / 27 40 24 37 Vicksburg 69 90 70 89 / 27 44 20 31 Hattiesburg 67 89 67 89 / 28 54 28 51 Natchez 69 89 69 88 / 28 47 21 46 Greenville 70 88 71 88 / 30 41 15 26 Greenwood 69 89 70 89 / 27 37 16 25 && .JAN WATCHES/WARNINGS/ADVISORIES... MS...None. LA...None. AR...None. &&
Hazardous Weather Outlook National Weather Service Jackson MS 209 PM CDT Mon May 21 2018 ARZ074-075-LAZ007>009-015-016-023>026-MSZ018-019-025>066-072>074- 221915- Ashley-Chicot-Morehouse-West Carroll-East Carroll-Richland- Madison LA-Franklin LA-Catahoula-Tensas-Concordia-Bolivar- Sunflower-Leflore-Grenada-Carroll-Montgomery-Webster-Clay-Lowndes- Choctaw-Oktibbeha-Washington-Humphreys-Holmes-Attala-Winston- Noxubee-Issaquena-Sharkey-Yazoo-Madison MS-Leake-Neshoba-Kemper- Warren-Hinds-Rankin-Scott-Newton-Lauderdale-Claiborne-Copiah- Simpson-Smith-Jasper-Clarke-Jefferson-Adams-Franklin MS-Lincoln- Lawrence-Jefferson Davis-Covington-Jones-Marion-Lamar-Forrest- 209 PM CDT Mon May 21 2018 This hazardous weather outlook is for portions of southeast Arkansas, northeast Louisiana, central Mississippi, north central Mississippi, and south central Mississippi. .DAY ONE...Tonight and Tuesday The probability for widespread hazardous weather is low. .DAYS TWO THROUGH SEVEN...Tuesday night through Sunday The probability for widespread hazardous weather is low. .SPOTTER CALL TO ACTION STATEMENT... The activation of storm spotters, HAM radio operators, and emergency management personnel in support of severe weather operations is not expected through next Sunday. 21 && ...HAZARD LEGEND... No short term hazards expected. ...USEFUL WEATHER WEB PAGES (URLS)... NWS JAN Home page... https://www.weather.gov/jan Stay Aware, Stay Safe NWS JAN Briefing Page... https://www.weather.gov/jan/safe Latest Weather Briefing... https://www.weather.gov/jan/weather_briefing Find NWS JAN on Facebook... https://www.facebook.com/NWSJacksonMS Follow NWS JAN on Twitter... @NWSJacksonMS Follow NWS JAN on Youtube... https://www.youtube.com/user/NWSJacksonMiss
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE JACKSON MS
400 PM CDT MON MAY 21 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0325 PM HAIL 5 W RICHLAND 32.24N 90.25W
05/21/2018 E1.00 INCH HINDS MS TRAINED SPOTTER
NEAR THE INTERSECTION OF SPRYFIELD RD AND
TIFTON DR.
&&
TWPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE JACKSON MS
404 PM CDT MON MAY 21 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0402 PM HAIL 1 ESE BRANDON 32.27N 89.99W
05/21/2018 E0.25 INCH RANKIN MS LAW ENFORCEMENT
PEA SIZE HAIL IN DOWNTOWN BRANDON.
&&
TWSpecial Weather Statement
National Weather Service Jackson MS
411 PM CDT MON MAY 21 2018
MSZ049-212145-
Rankin MS-
411 PM CDT MON MAY 21 2018
...A STRONG THUNDERSTORM WILL AFFECT CENTRAL RANKIN COUNTY UNTIL 445
PM CDT...
At 410 PM CDT, Meteorologists were tracking a strong thunderstorm
near Fannin, or near Brandon, moving northeast at 15 mph.
Dime size hail and wind gusts up to 50 mph will be possible with this
storm.
This strong thunderstorm will be near...
Fannin around 420 PM CDT.
Goshen Springs around 440 PM CDT.
Pisgah around 445 PM CDT.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
High winds can bring down trees and large limbs resulting in serious
injury or property damage. Exercise extreme caution when outdoors
during such strong winds...and be especially aware of older trees.
&&
LAT...LON 3226 8983 3226 9005 3244 9005 3247 9002
3257 8980
TIME...MOT...LOC 2110Z 207DEG 13KT 3236 8994
DBPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE JACKSON MS
437 PM CDT MON MAY 21 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0322 PM TSTM WND DMG 5 SW JACKSON 32.27N 90.28W
05/21/2018 HINDS MS PUBLIC
TREE DOWN ACROSS RAYMOND RD BETWEEN PLUMMER
CIR AND MADDOX RD.
&&
TWSpecial Weather Statement National Weather Service Jackson MS 514 PM CDT MON MAY 21 2018 MSZ018-212300- Bolivar MS- 514 PM CDT MON MAY 21 2018 ...A STRONG THUNDERSTORM WILL AFFECT SOUTHEASTERN BOLIVAR COUNTY UNTIL 600 PM CDT... At 513 PM CDT, Meteorologists were tracking a strong thunderstorm near Scott, or 12 miles northwest of Leland, moving east at 10 mph. Dime size hail and winds in excess of 40 mph will be possible with this storm. This storm will remain over mainly rural areas of southeastern Bolivar County. PRECAUTIONARY/PREPAREDNESS ACTIONS... High winds can bring down trees and large limbs resulting in serious injury or property damage. Exercise extreme caution when outdoors during such strong winds...and be especially aware of older trees. && LAT...LON 3367 9078 3353 9084 3353 9110 3366 9107 TIME...MOT...LOC 2213Z 278DEG 8KT 3357 9100 DB
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE JACKSON MS
523 PM CDT MON MAY 21 2018
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0523 PM FLASH FLOOD 1 S DERMOTT 33.52N 91.44W
05/21/2018 CHICOT AR TRAINED SPOTTER
GIBSON CIR DR UNDERWATER.
&&
TWThe Little Rock radar (KLZK), 165 km away, was scanning. The volume nearest the first event began at 22:24 UTC.
1 flash flood. Local standard time, as filed.
Gibson Circle Drive was under water.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Arkansas in 2018Every state in 2018This day in weather historyWarnings in Arkansas, May 2018
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 748135.